//#include<iostream>
//using namespace std;
//int mul(int x, int y) { return x * y; }
//int mul(int x, int y, int z) { return x * y * z; }
//int main()
//{
//	int  a = 3, b = 4, c = 5;
//	cout << a << '*' << b << '=' << mul(a, b) << endl;
//	cout << a << '*' << b << '*' << c << '=' << mul(a, b, c) << endl;
//	return 0;
//}